Method for forming rivets.



No.860,624. PATENTEDJUL'Y23,1907. V w. P. BARTEL.

METHOD FOR FORMING RIVETS.

APPLICATION FILED JAN. 5, 1907.

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5 UNITED STATES PATENT OFFICE.

WILLIAM P. B'ARTEL, OF WALTHAM, MASSACHUSETTS, ASSIGNOR TO .IUDSON L. THOMSON MFG COMPANY, A CORPORATION OF MAINE.

METHOD FOR FORMING RIVETS. I

Specification of Letters Patent. I

- Patented July as, 1907.

Application filed January 6, 1907. Serial No- 350,874.

substantially cylindrical in form, said recess being frusto-conical in shape and inclosing therein a head preferably formed of hardened metal and having a frusto-conical basewhich fits in said recess, whereby the two parts of the rivet are locked one to the other so that they cannot be separated in the practical use for which said rivet is designed to be used.

The invention consists in the method of forming two.

.part rivets hereinafter described and particularly pointed out in the claims.

Referring to the drawings: Figure 1 is a plan view of a portion of the rivet designed to be formed by my improved method. Fig. 2 is a section taken on line 2-2, Fig. 1. Fig; 3 is a plan view of the two parts of the rivet with the shank partially formed and the head inclosed in the recess formed in the upper face of said shank. Fig. 4 is a. section taken on line 44, Fig. 3. Fig. 5 is a plan view of the completed rivet and the female die by which the last process in the operation of forming. the rivet is obtained. Fig. 6 is a section taken on line 6-6, Fig. 5, showing both male and female dies, said dies being broken away.

Like numerals refer to like parts throughout the several views of the drawings. I

In the drawings, 10 is the shank of the rivet, 11 the flange, 12 the rim, 13 the stem, 14 the recess in the upper face of the shank, and 15 the head formed preferably of hardened metal. In Figs. 1 and 2, the shank i s' illustrated as formed by suitable dies in their first forming operation, the same being a flat headed rivet consisting of a stem 13 and a flange 11, the rim 12 of said flange decreasing in thickness from the outer periphery of the flange toward the stem 13.

l The second step in the method of forming the shank and rivet consists in forming the shank illustrated in .Fig. 2 into the form illustrated in Fig. 4, that is, the

ing that of acylinder.

form, said annular .rim surrounding a recess 14 preferably cylindrical, The head 15 is then placed in the recess 14 and the head and shank forced downwardly into a cylindrical recess 16 in the female die 17, the

same being driven into said female die by the male die 18, Fig. 6; This last operation crowds the rim 12 inwardly until the recess 14 becomes a 'frusto-conical recess and the periphery of the flange 11 becomes a-cylinder so that the head 15 which isformed. preferably with a frusto-conical base 19 is locked to theflange 11.

As the male, die 18 is withdrawn the completed rivet is forced out of the female die by a suitably arranged spring 20.

While it is preferable in a completed rivet that the periphery of the same should be of cylindrical form, it is evident'that the same might be of conical form without departing from the spirit of my invention so long as the periphery of the flange 11 in the completed rivet more closely approaches a cylinder than the periphery of the flange prior to being forced into the final forming die, as illustrated in Fig. 4. It is also evident that the shape of the base of the head and the recess in the upper face of the flange might be varied without departing from the spirit of my invention so long as in the resulting structure the rim of the flange interlocks with thebase of the head. For instance, the base of the head might have a projection thereon which would'project into a recess in the rim of the flange and this recess in the rim of the flange might be formed in the upper face of the flat headed rivetillustrated in Fig. 2 during the same operation as that in which said flange is formed upon the stem 13 without departing from thespirit of my inventiont It is moreover obvious that the flange 11 might be formed (as in Fig.4) by drilling or boring a recess 14 in the upper face of the flange and then forming said flange by means of the male and female dies as shape of the recess in whichsaid head is located and thus locking the parts together at the same time changing the form of the periphery of the flange from a. frustoconical formation to a cylindrical'formation or from a are Having thus described my invention, what I claim .and desire by Letters Patent'to secure is:

The hereindescribed method of manufacturing two part rivets, consisting; in first, forming a blank consisting 01' a shank and a flange integral therewith, said flange increasing in thickness toward the periphery thereof; second,

turning the periphery of said flange upwardly to form a cup, the diameter at the mouth of the opening of said cup being at least as great as at the base of said'cup; third,

In testimonywhereof I have hereunto set my hand in presence of two subscribing witnesses.

WILLIAM P. BARTEL.

Witnesses:

CHARLES S. GQODING, ANNIE J. BAILEY. 

